middleware

func LogRequest ¶

func LogRequest() goa.Middleware

LogRequest creates a request logger middleware. This middleware is aware of the RequestID middleware and if registered after it leverages the request ID for logging.

func LogResponse ¶

func LogResponse() goa.Middleware

LogResponse creates a response logger middleware. Only Logs the raw response data without accumulating any statistics.

func Recover ¶

func Recover() goa.Middleware

Recover is a middleware that recovers panics and returns an internal error response.

func RequestID ¶

func RequestID() goa.Middleware

RequestID is a middleware that injects a request ID into the context of each request. Retrieve it using ctx.Value(ReqIDKey). If the incoming request has a RequestIDHeader header then that value is used else a random value is generated.

func RequireHeader ¶

func RequireHeader(
	pathPattern *regexp.Regexp,
	requiredHeaderName string,
	requiredHeaderValue *regexp.Regexp,
	failureStatus int) goa.Middleware

RequireHeader requires a request header to match a value pattern. If the header is missing or does not match then the failureStatus is the response (e.g. http.StatusUnauthorized). If pathPattern is nil then any path is included. If requiredHeaderValue is nil then any value is accepted so long as the header is non-empty.

func Timeout ¶

func Timeout(timeout time.Duration) goa.Middleware

Timeout sets a global timeout for all controller actions. The timeout notification is made through the context, it is the responsability of the request handler to handle it. For example:

func (ctrl *Controller) DoLongRunningAction(ctx *DoLongRunningActionContext) error {
	action := NewLongRunning()      // setup long running action
	c := make(chan error, 1)        // create return channel
	go func() { c <- action.Run() } // Launch long running action goroutine
	select {
	case <- ctx.Done():             // timeout triggered
		action.Cancel()         // cancel long running action
		<-c                     // wait for Run to return.
		return ctx.Err()        // retrieve cancel reason
	case err := <-c:   		// action finished on time
		return err  		// forward its return value
	}
}

Package golang.org/x/net/context/ctxhttp contains an implementation of an HTTP client which is context-aware:

func (ctrl *Controller) HttpAction(ctx *HttpActionContext) error {
	req, err := http.NewRequest("GET", "http://iamaslowservice.com", nil)
	// ...
	resp, err := ctxhttp.Do(ctx, nil, req) // returns if timeout triggers
	// ...
}

Controller actions can check if a timeout is set by calling the context Deadline method.